Milwaukee, Ozaukee, Racine, Kenosha and Sheboygan are all under a poor air quality alert from noon to 11 p.m., according to the National Weather Service. The air quality index is expected to reach the "unhealthy for sensitive groups" to even the generally "unhealthy" level throughout the afternoon and evening, NWS says.

The 'unhealthy for sensitive groups' air quality in Chicago comes as an air quality alert was issued for the entire state of Wisconsin.